GCSE Chemistry

The flashcards below were created by user
ghoran
on FreezingBlue Flashcards.

what are the advantages of bio-leaching

the costs of seting up this bio-leaching is low

it does not need huge open cast mines that scar the landscape

bacteria can get the copper from low grade ores or waste

it uses a lot less energy and does not produce sulfur dioxide gas as in smelting sulfied ores

it can be used on ores that would pollute the air when smelted

what are the disadvantages of bioleaching

biol-leaching does not recover precious metals , so this reduces profits for the copper refiners

sometimes acid has to be added to the ore - which costs money

sometimes the bacteria themselves produce too much acid - which has to be neutralised again this cost more money

it can take years to extract only 50% of the copper from the ores . So reasearch continues to speed up the action of the bacteria . However , as sources of high grade copper ore run out , bio-leaching will get more and more important

purification of copper - copper is a very good ..... of electricity , it is used for electrcial ..... and cables . However small amountos of ..... cut down this conductivity quite noticeably . to ensure a high level of purity newly extracted copper had to be ...... by ..... . the electrolyte is ..... ..... . when the current flows , the copper moves from the .... electrode to the .... elctrode . any .... fall to the bottom of the cell and collect below the ... electrode in the from of ..... . this .... is rich in precious .... and the recovery of these metals is an important aspect of the economies of the process

conductor

wiring

impurities

purified

electrolyisis

copper sulphate

impure

pure

impurities

+

slime

slime

metals

how can we concentrate copper carbonate write a balanced symbol and word equation

copper carbonate[heat]====> copper oxide + carbon dioxide

CuCO3{heat}===> CuO + CO2

how can we extract copper oxide
write a word equation and balanced symbol equation

by smelting

copper oxide + carbon =====> copper + carbon dioxide

2CO + C ====> 2Cu + CO2

how can we extract copper sulphate , write a word equation and balanced symbol equation

scarp iron can be used in a displacement reaction because iron is higher in the reactivity series than copper

Copper sulphate + iron ====> iron sulphate + copper

CuSO4 + Fe ====> FeSO4 + Cu

Explain how the blast of air in a blast frunace helps to raise the temperature

because it allows the coal to burn faster because the air contains oxygen which will burn with the coal to produce CO2 , a waste gas in the blast furnace

limestone reacts with any sand ( SiO2 ) in an iron ore to form calcium silicate . Comlpete the balanced chemical equation

CaCO3 + SiO2 ===> CaSiO3 + .........

CO2

write a word equation for the extraction or iron in a blast furnace

iron oxide + carbon ====> iron + cabron dioxide

if iron oxide is Fe2O3 write a balanced symbol equation for the extraction of iron in a blast frunace

because there would be too much waste produced and it would be very inefficient

exlpain why copper collects at the negative terminal during electrolysis

because it wants to collect 2e- in order to become a neutral copper atom , and oppisites attract

draw a flow chart for the production of copper from low grade ores by leaching

soak copper in acid or water

are the copper compounds leached out - if no repeat the above stage , if yes move onto the next stage

remove the copper from the lechate by electrolysis

can you suggest a method for cleaning up rivers polluted with copper salts ? what are the disadvanatges

Iron is more reactive than copper salts so if we put scarp iron in these rivers , the iron will then displace the copper from the solution . the copper can then be refined and collected

however there are many disadvantages

the river will then be polluted with iron salts

ans somebody could steal the scrap iron

in general recycling

saves resources

saves energy

reduces pollution

reduces mining

what are the neagtives or recycling

people need to collect and sort the recycled items , this will involve paying labourers , also the vechiles are expensive to use in terms of tax and fuel , and also burning fuel produces carbon dioxide which leads to global warming

draw a flow chart to show the process of recycling

phtomining - the plants which absorb metal compounds are called

hyper-accumulators

we can extract cobalt , nickel and cadimium using phytomining from the :

brasicas family

what are the brasiscas family otherwise known as

the cabbage family

what is an advanatge of phytoming

it is cheap

doesnt release any greenhouse gases

sustainable

what are the disadvantages of phytomining

the planst will struggle to survive as they are purposley put in areas where the soil contains metal ores , therefor it is too toxic for the soil and plant

for sucess you are relying on the plant and many things could affect the plants such as the weather , without a healthy plant your extraction may not be sucessfull